This is an investigation of the individuality, variability and long-term stability of the chemistry and physiology of human health to establish a scientifically sound basis for health maintenance and preventive medicine. The unique individuality and narrow ranges of individual physiological variations of chemical, hematological, physiological and physical measurements provide a unique profile of health reference data as a basis for comparison and evaluation of subsequent test results which deviate outside the person's individual range of values. Long-term studies extending over 10 to 20 years will be required to document the differences in health patterns of people of different lifestyles, habits, occupational hazards, stresses and genetic make-up, and to discover the subtle changes associated with or predictive of at-risk states and early degenerative pathology. To discover the laboratory measurements which are most descriptive of a healthy physical and mental state and most sensitive to early changes an evaluation survey of many laboratory analytical procedures is necessary. Continued development of automated micro methods and improvement of precision and quality control will provide the necessary quality and long-term quantitative reliability and materially reduce costs. An advanced design mini-computer processing system converts, sorts and generates profile reports and graphic charts. Further development will provide physiological interpretive correlations and individual biomathematical simulation models for periodic updating and statistical analyses.